Methods and apparatus for random access with contention resolution message repetition

ABSTRACT

A method may include sending a contention resolution message for a random access procedure from a user equipment (UE) through a physical uplink channel in a wireless communication network, and sending a repetition of the contention resolution message from the UE through the physical uplink channel. The physical uplink channel may include a physical uplink shared channel (PUSCH). The method may further include selecting a preamble from a first preamble group corresponding to a capability of the UE to send the repetition of the contention resolution message, and sending the preamble from the UE. Selecting the preamble from the first preamble group may include selecting a preamble from a first preamble sub-group corresponding to the capability of the UE to send the repetition of the contention resolution message.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to, and the benefit of, U.S.Provisional Patent Application Ser. No. 63/021,078 titled “System andMethod For Msg3 Coverage Enhancement” filed May 6, 2020 which isincorporated by reference, and U.S. Provisional Patent Application Ser.No. 63/134,580 titled “System and Method for Msg3 Coverage Enhancement”filed Jan. 6, 2021 which is incorporated by reference.

TECHNICAL AREA

This disclosure relates generally to wireless networks, and specificallyto methods and apparatus for random access with contention resolutionmessage repetition.

BACKGROUND

A wireless network may implement a random access procedure to enable auser equipment (UE) such as a cellular handset to establish a connectionwith a base station. During a random access procedure, a UE may send acontention resolution message to a base station.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not constitute prior art.

SUMMARY

A method may include sending a contention resolution message for arandom access procedure from a user equipment (UE) through a physicaluplink channel in a wireless communication network, and sending arepetition of the contention resolution message from the UE through thephysical uplink channel. The physical uplink channel may include aphysical uplink shared channel (PUSCH). The method may further includeselecting a preamble from a first preamble group corresponding to acapability of the UE to send the repetition of the contention resolutionmessage, and sending the preamble from the UE. Selecting the preamblefrom the first preamble group may include selecting a preamble from afirst preamble sub-group corresponding to the capability of the UE tosend the repetition of the contention resolution message. The method mayfurther include selecting a first set of resources for a preambletransmission corresponding to a capability of the UE to send therepetition of the contention resolution message, and sending a preamblefrom the UE using the first set of resources. The contention resolutionmessage may be sent using a first set of resources. The repetition ofthe contention resolution message may be sent using a second set ofresources. The first set of resources may be configured substantiallyindependently of the second set of resources. A portion of the first setof resources may be configured substantially the same as a portion ofthe second set of resources. The first set of resources may include afirst repetition value (RV), and the second set of resources may includea second RV that may be different from the first RV. The first set ofresources may include a first RV, and the second set of resources mayinclude a second RV that may be the same as the first RV. The first setof resources may have a first configuration for a first transmissioncomprising the contention resolution message, and the first set ofresources may have a second configuration for a second transmissioncomprising the contention resolution message, wherein the secondconfiguration may be substantially different from the firstconfiguration. The first set of resources may have a first configurationfor a first transmission comprising the contention resolution message,and the first set of resources may have a second configuration for asecond transmission comprising the contention resolution message,wherein the second configuration may be substantially the same as thefirst configuration. The first set of resources may include an RV index.The method may further include configuring the RV index dynamically. Themethod may further include configuring the RV index semi-statically. Thefirst set of resources may include a demodulation reference signal(DMRS) configuration. The method may further include sending to the UEan index to one or more resources of the first set of resources. Themethod may further include monitoring a response based on completion ofsending the contention resolution message. The method may furtherinclude monitoring a response based on completion of sending therepetition of the contention resolution message. The method may furtherinclude performing a power adaptation for the physical uplink channel.The method may further include configuring a first set of parameters forthe power adaptation, and configuring a second set of parameters for thepower adaptation. The UE may include a first UE, the contentionresolution message may include a first contention resolution message,and the method may further include using the first set of parameters tosend the first contention resolution message from the first UE using thephysical uplink channel, and using the second set of parameters to senda second contention resolution message from a second UE through thephysical uplink channel. The method may further include changing one ormore of the parameters between the contention resolution message and therepetition of the contention resolution message.

An apparatus may include a user equipment (UE) for a wirelesscommunication network, the UE including a controller configured to senda contention resolution message for a random access procedure through aphysical uplink channel in the wireless communication network, and senda repetition of the contention resolution message through the physicaluplink channel. The physical uplink channel may include a physicaluplink shared channel (PUSCH).

An apparatus may include a base station for a wireless communicationnetwork, the base station including a controller configured to receive acontention resolution message for a random access procedure through aphysical uplink channel in the wireless communication network, andreceive a repetition of the contention resolution message through thephysical uplink channel. The physical uplink channel may include aphysical uplink shared channel (PUSCH).

A method may include sending a contention resolution message for arandom access procedure from a user equipment (UE) through a physicaluplink channel in a wireless communication network, and performing apower adaptation for the physical uplink channel based on sending thecontention resolution message. The method may further includeconfiguring a first set of parameters for the power adaptation, andconfiguring a second set of parameters for the power adaptation.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are not necessarily drawn to scale and elements of similarstructures or functions are generally represented by like referencenumerals or portions thereof for illustrative purposes throughout thefigures. The figures are only intended to facilitate the description ofthe various embodiments described herein. The figures do not describeevery aspect of the teachings disclosed herein and do not limit thescope of the claims. To prevent the drawing from becoming obscured, notall of the components, connections, and the like may be shown, and notall of the components may have reference numbers. However, patterns ofcomponent configurations may be readily apparent from the drawings. Theaccompanying drawings, together with the specification, illustrateexample embodiments of the present disclosure, and, together with thedescription, serve to explain the principles of the present disclosure.

FIG. 1A illustrates an embodiment of a processing chain for one or moredownlink channels in accordance with example embodiments of thedisclosure.

FIG. 1B illustrates an embodiment of a processing chain for one or moreuplink channels in accordance with example embodiments of thedisclosure.

FIG. 2 illustrates an example embodiment of a 4-step random access (RA)procedure for an NR wireless network in accordance with the disclosure.

FIG. 3A illustrates an example embodiment of HARQ downlink scheduling inaccordance with example embodiments of the disclosure.

FIG. 3B illustrates an example embodiment of HARQ uplink scheduling inaccordance with example embodiments of the disclosure.

FIG. 4 illustrates an embodiment of a redundancy version scheme inaccordance with example embodiments of the disclosure.

FIG. 5A illustrates an embodiment of a random access procedure in whicha UE may send a contention resolution message with repetitions inaccordance with example embodiments of the disclosure.

FIG. 5B illustrates an example embodiment of a 4-step random access (RA)procedure for an NR wireless network with contention resolution messagerepetition in accordance with the disclosure.

FIG. 6 illustrates some embodiments of msg3 transmissions withrepetitions in an NR system in accordance with example embodiments ofthe disclosure.

FIG. 7 illustrates an example of a preamble pool grouping to indicate aUE capability such as the ability to send a contention resolutionmessage with repetitions in accordance with example embodiments of thedisclosure.

FIG. 8 illustrates an example of a scheme for using resource sets toindicate a UE capability such as the ability to send a contentionresolution message with repetitions in accordance with exampleembodiments of the disclosure.

FIG. 9 illustrates an example of a scheme for sending a contentionresolution message with repetitions using independent resourceallocation in accordance with example embodiments of the disclosure.

FIG. 10 illustrates an example of a scheme for sending a contentionresolution message with repetitions using coupled resource allocation inaccordance with example embodiments of the disclosure.

FIG. 11 illustrates an example of a scheme for representing and/orconveying resource allocations using a list in accordance with exampleembodiments of the disclosure.

FIG. 12 illustrates an example of a scheme for representing and/orconveying resource allocations using multiple lists in accordance withexample embodiments of the disclosure.

FIG. 13 illustrates an example embodiment of a UE in accordance withexample embodiments of the disclosure.

FIG. 14 illustrates an example embodiment of a base station inaccordance with example embodiments of the disclosure.

FIG. 15 illustrates an embodiment of a method for random access in awireless communication network in accordance with example embodiments ofthe disclosure.

DETAILED DESCRIPTION Overview

This disclosure encompasses numerous inventive principles relating torandom access in wireless systems. These principles may have independentutility and may be embodied individually, and not every embodiment mayutilize every principle. Moreover, the principles may also be embodiedin various combinations, some of which may amplify the benefits of theindividual principles in a synergistic manner.

Some of the principles relate to sending a contention resolution messagewith repetitions. For example, during a random access procedure, a userequipment (UE) may send a contention resolution message to a basestation and then send one or more repetitions of the contentionresolution message to the base station. In some embodiments, acontention resolution message may be sent with repetitions regardless ofwhether the contention resolution message is part of an initialtransmission or a retransmission scheduled by the base station.

Some additional principles relate to techniques for informing a basestation of the capability of a UE to send a contention resolutionmessage with repetitions. For example, in some embodiments, a UE mayselect a preamble from a group and/or sub-group of preambles that havebeen configured to indicate one or more capabilities of the UE. Sendingthe selected preamble to the base station may indicate the one or morecapabilities of the UE to send a contention resolution message withrepetitions. In some other embodiments, a UE may select a set ofpreamble transmission resources that have been configured to indicateone or more capabilities of the UE. Sending a preamble to the basestation using the selected resources may indicate the one or morecapabilities of the UE to send a contention resolution message withrepetitions. In some further embodiments, a combination of preambleselection and resource selection may be used to indicate thecapabilities of the UE to send a contention resolution message withrepetitions.

Some additional principles relate to techniques for configuringresources for sending a contention resolution message with repetitions.For example, in some embodiments, resources for initially sending acontention resolution message may be configured independently ofresources for sending repetitions of the contention resolution message.In some other embodiments, resources for initially sending a contentionresolution message and resources for sending repetitions of thecontention resolution message may be configured in a coupled manner(e.g., one or more of the resources may be the same or similar). In somefurther embodiments, resources for initial sending and repetitions ofthe contention resolution message may be configured in a combination ofindependent and coupled manners.

As a further example, in some embodiments, resources for sending acontention resolution message with repetitions may be configureddynamically (e.g., a different set of resources may be used each time aUE performs a random access procedure). In some other embodiments,resources for sending a contention resolution message with repetitionsmay be configured semi-statically (e.g., a single set of resources maybe pre-configured via radio resource control (RRC) signaling and used bythe UE for all random access procedures until the set of resources ischanged via RRC signaling). In some further embodiments, a combinationof dynamic and semi-static resource configuration may be used forsending a contention resolution message with repetitions.

Some additional principles relate to techniques for conveying resourceallocation information from a base station to a UE for use in sending acontention resolution message with repetitions. For example, in someembodiments, a list of resources for sending a contention resolutionmessage with repetitions may be sent from a base station to a UE. Insome other embodiments, a base station may send the UE an index to anentry in a pre-configured list of resources.

Some additional principles relate to techniques for monitoring for aresponse from a base station. For example, in some embodiments, a UE maystart a monitoring window after completing the initial sending of acontention resolution message. In some other embodiments, a UE may starta monitoring window after completing the sending of one or morerepetitions of the contention resolution message.

Some additional principles relate to techniques for power adaptationwhile sending contention resolution messages. For example, a UE may beconfigured with multiple sets of power adaptation parameters to usewhile sending contention resolution messages. In some embodiments, oneof the sets of power adaptation parameters may be selected by a basestation. In some other embodiments, one of the sets of power adaptationparameters may be selected by the UE. Power adaptation parameters may bestepped across retransmissions, across repetitions of contentionresolution messages, or combinations thereof.

EXAMPLE EMBODIMENTS

Some example embodiments of systems, apparatus, devices, processes,methods, and/or the like illustrating some possible implementationdetails according to this disclosure are described herein. Theseexamples are provided for purposes of illustrating the principles ofthis disclosure, but the principles are not limited to theseembodiments, implementation details, and/or the like. For example, someembodiments may be described in the context of 5G and/or New Radio (NR)wireless networks, but the principles may also be applied to any othertypes of wireless systems including 3G, 4G and/or future generations ofwireless networks, and/or any other networks with random accessprocedures.

Uplink and Downlink Signals

In some wireless communication systems in accordance with exampleembodiments of the disclosure, a UE may transmit different uplink (UL)signals to a base station. For example, in an NR system, a UE may use ULtransmissions to send a variety of information to a base station whichmay be referred to as a gNodeB or gNB.

The UE may send user data to the gNB using a specific configuration oftime and frequency resources referred to as a physical uplink sharedchannel (PUSCH). A multiple access (MAC) layer at the UE may provideuser data that is intended to be delivered to a corresponding MAC layerat the gNB. A physical (PHY) layer at the UE may receive the user datafrom MAC layer as input and output one or more corresponding PUSCHsignals through a PUSCH processing chain.

The UE may send control data to the gNB using a physical uplink controlchannel (PUCCH). The control data may be referred to as uplink controlinformation (UCI) and may be converted to a PUCCH signal through a PUCCHprocessing chain.

A UE may receive different downlink (DL) signals from the gNB. Forexample, in an NR system, a gNB may send a variety of information to theUE using different DL transmissions.

The gNB may send user data to the UE using a specific configuration oftime and frequency resources known as the physical downlink sharedchannel (PDSCH). A MAC layer at the gNB may provide user data that isintended to be delivered to the corresponding MAC layer at the UE. ThePHY layer at the gNB may receive the user data from the MAC layer dataas input and output the corresponding PDSCH signal through a PDSCHprocessing chain.

The gNB may send control data to the UE using a physical downlinkcontrol channel (PDCCH). The control data may be referred to as downlinkcontrol information (DCI) and may be converted into a PDCCH signalthrough a PDCCH processing chain.

RNTIs and Scrambling

Processing chains for signals such as PDCCH, PUCCH, PDSCH, and PUSCH inaccordance with example embodiments of the disclosure may involve theuse of scrambling codes. For example, in an NR system, scrambling codesmay be referred to as radio network temporary identifiers (RNTIs). Insome embodiments, different techniques may be used to apply RNTIs tocontrol channels and data (shared) channels. For control channels (e.g.,PDCCH and/or PUCCH), an RNTI may be used to scramble a portion of acyclic redundancy check (CRC) code before attaching it to the payload(e.g., DCI or UCI). For PDSCH and PUSCH, however, the RNTI may be usedto scramble the coded payload of the message.

FIG. 1A illustrates an embodiment of a processing chain for one or moredownlink channels in accordance with example embodiments of thedisclosure. The processing chain 100 illustrated in FIG. 1A may be used,for example, to implement processing chain for a PDSCH and/or a PDCCH.

The processing chain 100 may include a physical layer procedure 102having an input processing module 106 that may receive input data 104which may include MAC layer data for a PDSCH processing chain or DCIdata for a PDCCH processing chain. The input processing module 106 mayimplement one or more functions such as error correcting coding, CRC,rate matching, and/or the like. The physical layer procedure 102 mayfurther include a scrambling module 108 that may apply an RNTI 110 to anoutput of the input processing module 106. An output of the scramblingmodule 108 may be applied to an output processing module 112 that mayimplement one or more functions such as modulation, resource mapping,and/or the like, to generate a final output PDSCH or PDCCH 114.

FIG. 1B illustrates an embodiment of a processing chain for one or moreuplink channels in accordance with example embodiments of thedisclosure. The processing chain 150 illustrated in FIG. 1B may be used,for example, to implement processing chain for a PUSCH and/or a PUCCH.

The processing chain 150 may include a physical layer procedure 152having an input processing module 156 that may receive input data 154which may include MAC layer data for a PUSCH processing chain or UCIdata for a PUCCH processing chain. The input processing module 156 mayimplement one or more functions such as error correcting coding. CRC,rate matching, and/or the like. The physical layer procedure 152 mayfurther include a scrambling module 158 that may apply an RNTI 160 to anoutput of the input processing module 156. An output of the scramblingmodule 158 may be applied to an output processing module 162 that mayimplement one or more functions such as modulation, resource mapping,and/or the like, to generate a final output PUSCH or PUCCH 164.

Different types of RNTIs may be used for different procedures in an NRsystem in accordance with example embodiments of the disclosure. Forexample, a random access RNTI (RA-RNTI) may be used during a randomaccess (RA) procedure such as a 4-step random access channel (RACH)procedure before a connection is established between a UE and a gNB. Asanother example, once a UE has established a connection with a gNB, itmay obtain a cell RNTI (C-RNTI) which may be used for scheduling unicastPDSCHs. Some types of RNTIs such as C-RNTIs may be unique to anestablished connection between the gNB and one UE. However, some othertypes of RNTIs such as RA-RNTIs may be shared by multiple UEs (e.g., mayhave common values between UEs.)

Search Space and CORESET

Some UEs in an NR system in accordance with example embodiments of thedisclosure may be provided with a search space set configuration and/ora control resource set (CORESET) configuration for monitoring DCI in aPDCCH in a serving cell. In some embodiments, a search space setconfiguration may provide PDCCH monitoring occasion information in atime domain, and each monitoring occasion may be associated with aCORESET configuration linked to the search space set configuration. ACORESET configuration may provide a set of resource blocks (RBs) and/ora symbol duration for PDCCH candidate monitoring where a PDCCH candidatemay include a set of control channel elements (CCE) depending on anaggregation level. For example, in some embodiments, a CCE may include asix resource element group (REG), wherein each REG may include a groupof 12 consecutive resource elements (RE). Thus, a UE may monitor a setof REs for PDCCH candidates located in a specified time and/or frequencydomain based on the CORESET and/or search space set configurations. Inan NR system, different DCI formats may be used to convey differentcontrol information to the UE from the gNB. Table 1 illustrates someexamples of DCI formats that may be used in accordance with exampleembodiments of the disclosure.

TABLE 1 DCI Format Usage 0_0 Scheduling of PUSCH in one cell 0_1Scheduling of one or multiple PUSCH in one cell, or indicating downlinkfeedback information for configured grant PUSCH configured grantdownlink feedback information (CG-DFI) 0_2 Scheduling of PUSCH in onecell 1_0 Scheduling of PDSCH in one cell 1_1 Scheduling of PDSCH in onecell, and/or triggering one shot HARQ-ACK codebook feedback 1_2Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat, available RB sets, channel occupancy time (COT) duration andsearch space set group switching 2_1 Notifying a group of UEs of thePRB(s) and orthogonal frequency-division multiplexing (OFDM) symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs 2_4Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UEcancels the corresponding UL transmission from the UE 2_5 Notifying theavailability of soft resources 2_6 Notifying the power savinginformation outside discontinuous reception (DRX) Active Time for one ormore UEs 3_0 Scheduling of NR sidelink in one cell 3_1 Scheduling oflong term evolution (LTE) sidelink in one cell

Timing Adjustment

In an NR system in accordance with example embodiments of thedisclosure, communications between a UE and a gNB may be frame-based.During an initial access, UL transmissions from a UE may not betime-aligned with the gNB frame timing due to a roundtrip delay timethat may not be unaccounted for. In some embodiments, to synchronize theframe timing of the UE and the gNB (e.g., for UL and/or DLtransmissions), a physical random access channel (PRACH) may betransmitted from the UE to the gNB. The gNB may use the PRACH signal toestimate the roundtrip delay time. Based on the roundtrip delay time,the gNB may then inform the UE of a value of a timing adjustment (TA)the UE may apply to one or more UL transmissions to properly align theframe timing. Thus, during an initial access procedure, a UE may send aPRACH signal in addition to obtaining system information from the gNB asexplained in more detail below.

Random Access Procedure

FIG. 2 illustrates an example embodiment of a 4-step random access (RA)procedure for an NR wireless network in accordance with the disclosure.Prior to the start of an RA procedure, a base station 200, which in thisembodiment may be implemented as a gNB, may broadcast a masterinformation block (MIB) and one or more system information blocks (SIBs)to any UEs within range such as UE 202. The MIB/SIB transmission(s) mayinclude fundamental system information that a UE may use to communicateover the wireless network including information about the configurationof the RA procedure.

A random access message exchange may be initiated by the UE 202 when itsends a first message (msg1) including a random access preamble selectedfrom a pool of preambles to the gNB 200 over the PRACH which may beconfigured by the system information in the MIB/SIB. An identifier (ID)of the preamble chosen by the UE may be referred to as an RAPID. At thispoint, multiple UEs may potentially have initiated 4-step RA processessimultaneously. In some embodiments, each UE may use a preamble with adifferent RAPID.

After receiving msg1, the gNB 200 may send a second message (msg2) tothe UE which may include a random access response (RAR). In someembodiments, msg2 may include the RAPID of the preamble chosen by one UE(or in case of contention, multiple UEs), along with a TA value for theUE with the corresponding RAPID and a temporary C radio networktemporary identifier (TC-RNTI) which may be used by the UE 202 for therest of the RA procedure. Msg2 may also include a grant of UL resourcessuch as PUSCH time/frequency resources, modulation and coding scheme(MCS), transmission control protocol (TCP), and/or the like, the UE mayuse to send a contention resolution message (msg3) to the gNB.

After receiving msg2, the UE 202 may use the value of TA to adjust itsuplink timing. The UE 202 may then send msg3 to the gNB 200 using thePUSCH resources allocated by the uplink grant received in msg2. In someembodiments, msg3 may include contention resolution ID (CRID) that maybe provided by one or more higher layers above the physical layer of theUE. If multiple UEs have the same RAPID, all UEs may send msg3containing different CRIDs.

After receiving msg3, the gNB 200 may respond by sending a fourthmessage (msg4) which may include the CRID of one UE (e.g., UE 202). TheUE that has the corresponding CRID may then proceed to send anacknowledgement (ACK) message acknowledging the successful reception ofmsg4 and the initial access procedure. The temporary identifier TC-RNTImay then be promoted to a dedicated UE identifier C-RNTI.

Preamble Grouping

In some NR systems in accordance with example embodiments of thedisclosure, a collection of groups of non-intersecting preambles may beconfigured (e.g., by a gNB) within a cell. For example, two groups ofpreambles, Group A and Group B, may be pre-configured by the network toindicate different sizes of msg3 the UE 202 may transmit using thePUSCH. The groups of preambles may additionally, or alternatively,indicate information about the pathloss level between the UE and gNB.

When selecting a preamble to send with msg1, the UE may first select oneof the groups of preambles. The UE may then select a preamble fromwithin the selected group. For example, the UE 202 may select andtransmit a preamble from Group A if msg3 will be below a certainpre-determined size, but may otherwise select and transmit a preamblefrom Group B. Additionally, or alternatively, the UE 202 may select andtransmit a preamble from Group A if the pathloss between the UE and gNBis below a pre-configured threshold, but may otherwise select andtransmit a preamble from Group B.

Monitoring Responses from Base Station

During a random access procedure in accordance with example embodimentsof the disclosure, after the UE sends an initial message or contentionresolution message (e.g., msg1 or msg3), the UE may begin to monitor forthe expected reply (e.g., msg2 or msg4) from the gNB. For example, afterthe last symbol of msg1 or msg3 is transmitted, the UE may start amonitoring timer (which may establish a monitoring window) at the firstfollowing symbol of a CORESET where msg3 (msg4) scheduling DCI may beexpected to be received. The monitoring window duration may be RRCconfigured, for example, at the UE. If a retransmission is needed, theUE may receive a DCI 0_0 during the window scheduling a retransmissionof msg3. In some embodiments, the monitoring window may be restartedafter each retransmission.

If msg3 is not received correctly by the gNB, the gNB may request aretransmission of msg3 by the UE. A retransmission of msg3 may bescheduled, for example, by sending DCI format 0_0 from the gNB to theUE. In some embodiments, a msg3 retransmission may be performed with asymbol allocation identical to that used for the original msg3transmission. However, the scheduling DCI may specify the same or adifferent redundancy version (RV) to be used with the retransmission.

Power Adaptation

In some NR systems in accordance with example embodiments of thedisclosure, the transmission power P_(PUSCH) of the i-th retransmissionof msg3 may be expressed as

P _(PUSCH)(i)=min{P _(CMAX)(i),P _(O) _(PRE) +Δ_(PREAMBLE) _(Msg3) +10log₁₀(2^(μ) ·M(i))+α·PL+Δ _(TF) +f}  Eq. 1

where P_(CMAX) (i) may be the maximum transmission power allowed, P_(O)_(PRE) may be the preamble received target power configured by the RRCparameter preambleReceivedTargetPower, Δ_(PREAMBLE) _(Msg3) may be anadjustment factor determined by the RRC parameter msg3-DeltaPreamble,M(i) may be the number of allocated resource elements, PL may be themeasured path loss, α may be the pathloss compensation factor configuredby the parameter msg3-Alpha, Δ_(TF) may be the transport factor used forMCS adjustment, and f may be the closed loop power control factor.Moreover, the factor f may include a transmit power control (TPC)command δ_(msg2) and a power ramping factor provided by one or morehigher layers for the i-th transmission.

In some embodiments, the power ramping factor P_(msg3) ^(ramp) for msg3may be expressed as

P _(msg3) ^(ramp)(i)=C _(msg3)(i)*step_(msg3)  Eq. 2

where C_(msg3)(i) may be the ramping counter of msg3 at retransmissioni, and step_(msg3) may be the power ramping step for msg3, configured bythe parameter powerRampingStep.

Thus, in some embodiments, one or more of the following parameters maybe used to specify a power adaptation procedure for a msg3 transmission:preambleReceivedTargetPower, msg3-DeltaPreamble, msg3-Alpha, and/orpowerRampingStep.

Scheduling and HARQ

In some NR systems in accordance with example embodiments of thedisclosure, a gNB may dynamically schedule a PDSCH to one or more UEsthrough the use of one or more DCIs conveyed via a PDCCH. In someembodiments, an NR system may implement a closed-loop feedbacktransmission technique which may be referred to as hybrid automaticrepeat request (HARQ).

To apply HARQ to a downlink, an embodiment of a procedure for schedulinga PDSCH with feedback may be implemented as follows.

A gNB may transmit a PDCCH with DCI information that schedules resourcesfor receiving a PDSCH. The PDCCH may be transmitted using one set oftime/frequency resources chosen from a CORESET that may include multiplesets that may be continuously monitored by the UE. The PDCCH may bescrambled with a particular RNTI value.

Upon decoding the DCI, the UE may attempt to decode the correspondingPDSCH in the indicated resources. The PDSCH may be scrambled with thesame RNTI value used for the corresponding PDCCH.

In certain situations (for example, when the PDSCH is associated with aHARQ process), the gNB may indicate to the UE to send feedback inresponse to receiving the scheduled PDSCH. The feedback may includesending one or more UL signals as an Acknowledgement (ACK) or a NegativeACK (NACK) in response to the successful or failed decoding of PDSCH,respectively. In some embodiments of an NR system, the feedback may bepart of a HARQ process. In these situations, the gNB may indicate to theUE the resources to use for sending the HARQ ACK and/or NACK via thescheduling DCI (e.g., for unicast PDSCHs scrambled with C-RNTI). Inother situations, the UE may be indicated with the resources to use forsending HARQ feedback in the PDSCH payload (e.g., for receiving PDSCHcorresponding to msgB in 2-step RACH).

To apply HARQ to an uplink, a gNB may use DCIs to dynamically schedulePUSCH to be transmitted by one or more UEs. An embodiment of a procedurefor scheduling a PUSCH with feedback may be implemented as follows.

A gNB may transmit a PDCCH with DCI information that schedules resourcesfor transmitting a PUSCH. The PDCCH may be transmitted using one of theCORESETs that may be continuously monitored by the UE. The PDCCH may bescrambled with a particular RNTI value.

Upon decoding the DCI, the UE may prepare the PUSCH for an attemptedtransmission using the indicated resources. The PUSCH may be scrambledwith the same RNTI value used for the corresponding PDCCH.

In certain situations (for example, when the PUSCH is associated with aHARQ process), a UE may be expected to receive feedback from the gNB inresponse to receiving the scheduled PUSCH. The feedback may includesending one or more DL signals as an ACK or NACK in response to thesuccessful or failed decoding of the PUSCH, respectively. In thesesituations, the UE may be indicated with the resources to be used forreceiving the HARQ ACK and/or NACK via the scheduling DCI (e.g., forunicast PUSCHs scrambled with C-RNTI). In other situations, the UE maybe indicated with the resources for receiving HARQ feedback in thepayload of a previously received PDSCH (e.g., in the case of msg3transmission in 4-step RACH, where the resources for receiving HARQfeedback from the gNB may be provided in the UL grant in msg2).

Scheduling Timeline

In some NR systems in accordance with example embodiments of thedisclosure, resources may be scheduled from the gNB to the UE throughtechniques involving relative time offsets.

FIG. 3A illustrates an example embodiment of HARQ downlink scheduling inaccordance with example embodiments of the disclosure. FIG. 3Billustrates an example embodiment of HARQ uplink scheduling inaccordance with example embodiments of the disclosure.

In some embodiments, a gNB may use a PDCCH to provide a DL assignment toa PDSCH to indicate to a UE a relative slot offset from the slotcontaining the PDCCH to the slot containing the resources for the PDSCH.This slot offset may be referred to as K₀ as illustrated in FIG. 3A.Similarly, a time offset may be indicated to determine a slot for HARQfeedback relative to the slot containing the PDSCH. This slot offset maybe referred to as K₁ as illustrated in FIG. 3A. The gNB may alsoindicate resources for UL grants in UL scheduling by indicating a timeoffset from the slot containing the scheduling PDCCH to the slotcontaining the PUSCH resources. This offset may be referred to as K₂ asillustrated in FIG. 3B.

In some embodiments, when performing one or more tasks relating toscheduling transmissions for UEs, a gNB may adhere to one or moreconstraints pertaining to the relative timings of UL and DLtransmissions with respect to UE processing capabilities. For example,when a gNB schedules a DL transmission of a PDSCH, the gNB may attemptto ensure enough time for the UE to process the scheduling DCI and/orperform the reception and/or decoding of the transmitted PDSCH. Aprocess of accommodating one or more timing constraints may be referredto as adhering to a timeline. In some embodiments, a timeline for a UEmay include (1) enough time to receive, decode, and/or process thescheduling DCI, and/or (2) the time consumed by the UE to switch fromtransmission to reception, which may be referred to as UE switchingtime. For example, UE switching time may be accounted for inTime-Division-Duplex (TDD) systems. In cases in which a UE may bescheduled to transmit a corresponding HARQ ACK feedback, then thetimeline can also include (1) the time consumed by the UE to receive,decode, and/or process the scheduled PDSCH, and/or (2) the time requiredto prepare the corresponding HARQ feedback. Similar timing constraintsmay be implemented for scheduling PUSCHs.

Some embodiments may specify different processing timing requirementsfor UEs with different capabilities. For example, these requirements mayinclude (1) a minimum amount of time to allow for processing a PDSCH,which may be referred to as N₁, (2) a minimum amount of time to allowfor preparing and transmitting a PUSCH, which may be referred to as N₂,and/or (3) an amount of time that accounts for switching between UL andDL in TDD systems. In some embodiments, the values of such times maydepend on the processing capabilities of the UE. For example, UEs withbasic capabilities may have larger processing time constraints, whereasUEs with higher capabilities may have smaller processing timeconstraints. In some embodiments, when a UE establishes an RRCconnection, it may inform the gNB of its UE capabilities which may thenbe taken into consideration by the gNB when performing scheduling tasks.

HARQ and Redundancy Version

In some NR systems in accordance with example embodiments of thedisclosure, messages (e.g., PDSCHs and/or PUSCHs) associated with HARQprocesses may be encoded as follows. The PDSCH (or PUSCH) may first becoded with a base code with a mother coding rate. The codeword may thenbe punctured to achieve a target code rate indicated for the scheduledPDSCH (or PUSCH). In some embodiments, the puncturing pattern may bedetermined based on an RV. For example, an RV index may specify thestart and length of a sequence of parity bits retained in a particularPDSCH (or PUSCH) transmission. In some embodiments, there may be, forexample, four RV indices.

FIG. 4 illustrates an embodiment of a redundancy version scheme inaccordance with example embodiments of the disclosure. The embodimentillustrated in FIG. 4 includes four RV indices (0, 1, 2, and 3), acodeword with a mother code of 1/5, and a target code rate of 1/2. Inthe embodiment illustrated in FIG. 4, the transport block (TB) may havea length of x bits. The codeword sections shown as C₁, C₂, . . . mayinclude any number of bits. Retransmitted signals may use different RVindices when retransmissions are scheduled. This may allow the receiverto perform soft combining in which some or all retransmissions of the TBmay be combined, for example, to enhance the decoding performance of thereceiver.

Scheduling Retransmissions

In some NR systems in accordance with example embodiments of thedisclosure, retransmissions may be scheduled dynamically and/or usingpreconfigurations. As an example of dynamic rescheduling of DLtransmissions, if a PDSCH associated with a HARQ process has not beensuccessfully decoded, the UE may send a NACK feedback signal to the gNB.Upon receiving the NACK feedback, the gNB may reschedule a PDSCHtransmission to the UE via a new DCI indication to the UE. The new DCImay indicate that the scheduled PDSCH is not a new packet, for exampleby not toggling a new data indicator (NDI) field in the DCI. The DCI mayalso indicate the HARQ process with which the scheduled PDSCH isassociated, and/or the assumed RV index.

In some embodiments, similar behavior may be implemented for ULtransmissions. For example, if a PUSCH associated with a HARQ processhas not been successfully decoded, the gNB may schedule a retransmissionof the PUSCH. (In the case of a UL transmission, the gNB may not need tosend an explicit HARQ NACK feedback because it may simply schedule aretransmission). The rescheduling of the PUSCH may be performed, forexample, by transmitting a scheduling DCI with the NDI indicator nottoggled, and with an indication of the associated HARQ process andassumed RV index.

Alternatively, or additionally, some embodiments may allow automaticrepetitions of a transmission which may be scheduled along with theoriginal transmission. In some embodiments, repetition of a transmissionmay be referred to as aggregation. For example, in some embodiments, agNB may schedule a set of K transmissions of a PDSCH in a set of Kconsecutive slots, each with identical symbol allocations. Thesescheduled PDSCHs may include one first PDSCH containing a new payload,and K−1 repetitions of the first PDSCH. All transmissions may belong tothe same HARQ process, and each transmission may assume a particular RVindex. The sequence of RV indices assumed in all transmissions may beagreed upon between the gNB and the UE such that both the transmitterand receiver are in agreement on the RV index assumed in each slot. Thenumber of repetitions K of a PDSCH may be referred to as an aggregationfactor.

In some embodiments, the aggregation factor may be indicateddynamically, in which case the scheduling DCI may include a timeresource allocation indication. The resource allocation indication mayinclude an index to a time resource allocation table that may be RRCconfigured on the UE side. The time resource allocation table mayinclude an entry for the number of repetitions which may configure thenumber of repetitions K.

Alternatively, or additionally, the aggregation factor may be indicatedstatically, in which case a UE may be RRC configured with an aggregationfactor parameter that may specify the number of repetitions K that maybe employed for one or more PDSCHs scheduled with repetitions. In thiscase, the gNB may be unable, or only partially able, to dynamicallyindicate how many repetitions may be used in each scheduling of a PDSCHwith repetitions.

UE Capabilities

In some NR systems in accordance with example embodiments of thedisclosure, a gNB and/or UE may have the ability to implement carrieraggregation (CA). In a CA scheme, a UE may be able to use multiplecomponent carriers (CCs) for transmission, allowing the UE to utilize alarger bandwidth than would be possible using a single CC. Someembodiments may implement one or more of the following CA modes:intra-band frequency aggregation with contiguous CCs, intra-bandfrequency aggregation with non-contiguous CCs, and/or inter-bandfrequency aggregation with non-contiguous CCs.

In some embodiments, the categorization of CA modes may depend on thecollection of bands that may include the CCs that may be used for CA.This collection of bands may be referred to as a band combination. Insome embodiments of NR systems, CA may be applied across cells. Forexample, a UE may initially connect to one cell in the CA, which may bereferred to as the primary cell (PCell). The UE may then find andconnect to one or more other cells in the CA which may be referred to assecondary cells (SCells). The UE in CA may be able to use each cell fortransmission and/or reception of different combinations of signals. Forexample, a UE may be able to send and/or receive a PUSCH on one cell andsend and/or receive a sounding reference signal (SRS) on another cell.

Some embodiments may specify one or more timeline rules and/orconditions for such simultaneous transmission and/or reception ofsignals in CA. In addition, even with timeline rules and/orrequirements, some embodiments may not mandate that every NR-connectedUE be able to perform such simultaneous usage of CCs in CA. Moreover, aUE may have the capability of performing certain transmission and/orreception tasks in CA while not having the capability of performingother tasks. Another factor that may affect the UE capability may be theuse of FDD and/or TDD. For example, a UE may be able (or unable) toperform a task using FDD bands and/or band combinations, while it may beunable (or able) to perform the same task using TDD bands and/or bandcombinations. In some embodiments, to better utilize the capabilities ofa UE and improve or optimize the use of the network, the gNB may beinformed of the capabilities of a UE which it may then take into accountwhen the gNB schedules transmissions to and/or receptions from UEs inthe network.

In some embodiments, a UE capability may refer to a mechanism that maybe used to inform a gNB of the ability of a UE to perform certaintransmission and/or reception tasks. Each UE capability reported to thegNB may inform the gNB of the UE's ability to perform a particular task.A UE capability mechanism may provide a UE with flexibility to reportits capability in different transmission scenarios. The following aresome examples of possible techniques for reporting UE capabilities to agNB. Other techniques may also be used.

A UE may report its capability to perform certain tasks in any scenario.This may be referred to as a UE reporting a capability on a per-UEbasis.

A UE may report its capability to perform certain tasks in particularbands. This may be referred to as a UE reporting a capability on aper-band basis.

A UE may report its capability to perform certain tasks in particularband combinations in CA. This may be referred to as a UE reporting acapability on a per-bandCombination or per-BC basis.

A UE may report its capability to perform certain tasks in CA in certainsituations, e.g., not necessarily always for a given band combination.In this case, a mechanism which may be referred to as feature sets maybe used to allow for such flexibility in reporting, and this may bereferred to as a UE reporting a capability on a per-featureSet or per-FSbasis.

In some example embodiments, a UE capability may inform a gNB that a UEis able (or not able) to transmit certain UL signals in certain bands.The UE capability mechanism may have the flexibility to indicate thatthe UE may be able to perform a certain task in certain scenarios, whileit may be unable to perform the same task in other scenarios. Forexample, certain UE capabilities may be signaled to the gNB on aper-band basis, e.g., for one task, the UE may have differentcapabilities for different bands. Some UE capabilities may be universalacross bands and/or band combinations, thus, they may be per-UE based.In the case of CA, UE capabilities may be signaled on aper-band-combination basis. Thus, with respect to CA, the ability of aUE to perform certain tasks may depend on the combination of bandsinvolved in the CA.

Sending Contention Resolution Message with Repetitions

In some wireless networks in accordance with example embodiments of thedisclosure, a UE may be allowed to send a contention resolution messageto a base station with repetitions. For example, during a random accessprocedure in an NR system, a UE may send msg3 to a gNB with repetitionsusing a PUSCH.

In some embodiments, a UE may send a contention resolution message withrepetitions regardless of the context. For example, during a randomaccess procedure in an NR system, a UE may send msg3 with repetitionsduring a first attempted transmission of msg3, or during aretransmission of msg3. Moreover, although some embodiments may bedescribed in the context of systems in which a base station may performscheduling of a contention resolution message with repetitions, theinventive principles are not limited to any particular type ofscheduling. For example, in some embodiments, scheduling of a contentionresolution message with repetitions may be performed by one or more UEs,or by any other component, process, and/or the like. As another example,a UE may send a contention resolution message with repetitions during a2-step RA procedure, a 4-step RA procedure, and/or the like.

In some embodiments, sending a contention resolution message withrepetitions may refer to sending any number of repetitions of an initialcontention resolution message including zero, one, etc. In someembodiments sending a contention resolution message with repetitions mayrefer to the UE being allowed to send one or more repetitions,regardless of whether any repetitions of the initial contentionresolution message are ever sent. In some embodiments, a repetition of acontention resolution message may also refer to an initial contentionresolution message; thus, for example, sending an initial contentionresolution message with two repetitions may also be referred to assending three repetitions of the contention resolution message. Asanother example, sending K of the same contention resolution message maybe referred to as sending K repetitions of the contention resolutionmessage.

Although the inventive principles relating to sending a contentionresolution message with repetitions are not limited to any particularcontext, in some embodiments, they may be especially beneficial forimplementing coverage enhancement (CE). For example, in a CE scenario,due to poor channel quality, there may be a relatively high likelihoodthat the gNB may fail to decode a msg3 transmission from a UE. Thus, thegNB may reschedule multiple retransmissions of msg3 which may become abottleneck.

In some embodiments, allowing a UE to send a contention resolutionmessage with repetitions may enable a system to avoid unnecessaryscheduling of retransmissions. Moreover, depending on the implementationdetails, allowing a contention resolution message to be sent withrepetitions may also reduce latency, especially, for example, in CEscenarios in NR where retransmissions of msg3 are likely to be requiredby the gNB.

FIG. 5A illustrates an embodiment of a random access procedure in whicha UE may send a contention resolution message with repetitions inaccordance with example embodiments of the disclosure. In the embodimentillustrated in FIG. 5A, a UE 502 may send an initial contentionresolution message 504-1 to a base station 500. The UE 502 may beallowed to send one or more repetitions of the contention resolutionmessage 504-2 . . . 504-K to the base station 500. Depending on amonitoring technique that may be implemented to enable the UE 502 todetermine if the base station 500 has successfully decoded the initialcontention resolution message 504-1, the UE 502 may send any number fromzero through K of the repetitions of the contention resolution message504-2 . . . 504-K.

FIG. 5B illustrates an example embodiment of a 4-step random access (RA)procedure for an NR wireless network with contention resolution messagerepetition in accordance with the disclosure. The embodiment illustratedin FIG. 5B may be similar to the embodiment illustrated in FIG. 2,however, in the embodiment illustrated in FIG. 5B, msg3 may be sent withone or more repetitions.

In some embodiments, the UE 502 may send one or more of the messages504-1 . . . 504-K again, for example, if the base station 500 schedulesa retransmission of the initial contention resolution message withrepetitions.

In some NR systems in accordance with example embodiments of thedisclosure, a gNB may schedule a msg3 transmission with repetitionsdynamically, for example, using a scheduling DCI.

FIG. 6 illustrates some embodiments of msg3 transmissions withrepetitions in an NR system in accordance with example embodiments ofthe disclosure. In the embodiments illustrated in FIG. 6, time may berepresented on the horizontal axis, and frequency may be represented onthe vertical axis.

A gNB may schedule a first transmission of a msg3 with repetitions froma UE. The gNB may send a msg2 602 to the UE using a PDSCH and includinga UL grant with resources such as PUSCH time/frequency resources, MCS,TCP, RV index, and/or the like to be used by the UE to send msg3 and oneor more repetitions which, in this example, may include an initial msg3604, a first repetition of msg3 606, and a second repetition of msg3608. (As mentioned above, the three instances 604, 606, and 608 of msg3may alternatively be referred to as three repetitions of msg3.)

If the gNB fails to decode any of the instances 604, 606, and 608 ofmsg3, it may dynamically reschedule a retransmission of msg3 by sendinga PDCCH 610. The UE may respond to the PDCCH 610 by sending msg3 612 anda repetition of msg3 614.

If the gNB again fails to decode any of the instances 612 and 614 ofmsg3, it may dynamically reschedule another retransmission of msg3 bysending a PDCCH 616. The UE may respond to the PDCCH 616 by sending msg3618.

In some embodiments, during a 4-step RACH, the gNB may not be aware ofthe capability of a UE to implement msg3 with repetitions. Even if a UEperforms a 4-step RACH while RRC connected, the UE may not indicate itsC-RNTI to the gNB until the msg3 transmission. Thus, msg3 scheduling mayoccur while the gNB is not aware of the UE's capability to send msg3with repetitions.

In accordance with example embodiments of the disclosure, in addition toapplying one or more contention resolution message (e.g., msg3)enhancements to a UE, some additional principles relate to one or moretechniques for indicating an enhanced capability of a UE such as theability to send contention resolution message with repetitions. In someembodiments, the introduction of UE capabilities, and indication of suchcapabilities, regarding contention resolution message enhancement mayenable backward compatibility with UEs that do not have one or more suchcapabilities. However, in some embodiments, one or more of thetechniques relating to CE (e.g., sending a contention resolution messagewith repetitions) may be readily applicable even if such UE indicationis not present.

Preamble Grouping to Indicate UE Capabilities

In some wireless networks in accordance with example embodiments of thedisclosure, one or more dedicated sets of preambles may be used toenable a UE to indicate a UE capability to a base station. For example,in an NR system, a gNB may configure a preamble grouping per cell. Thegrouping may be indicted to UEs in the cell, for example, in the SIB.

FIG. 7 illustrates an example of a preamble pool grouping to indicate aUE capability such as the ability to send a contention resolutionmessage with repetitions in accordance with example embodiments of thedisclosure. The embodiment illustrated in FIG. 7 may be described in thecontext of an NR system, but the principles may be applied to any otherwireless network with RA procedures.

A first group of the preambles (e.g., group A) may be selected for useby a UE to indicate a CE capability such as sending a contentionresolution message with repetitions, while a second group of preambles(e.g., group B) may be selected for use by the UE to indicate a lack ofa CE capability. In some embodiments, the ratio of the sizes of thepreamble groups may be determined based, for example, on the expectednumber of UEs that may have CE capabilities to report, and the expectednumber of UEs that may not have CE capabilities to report.

In the embodiment illustrated in FIG. 7, preamble group A may be furthersplit into sub-groups (e.g., sub-group 1, sub-group 2, etc.) which mayindicate different UE capabilities. In the embodiment illustrated inFIG. 7, preamble group A may be split into sub-groups (e.g., to indicatea UE capability for sending msg3 with repetitions) because group A maybe more likely to be used in CE scenarios due to poor channelconditions. (For example, preambles in group A may be used if thepathloss between the UE and gNB is below a pre-configured threshold.) Inother embodiments, however, preambles in groups A and B, or only groupB, may be split into sub-groups (e.g., to indicate a UE capability suchas sending msg3 with repetitions).

Resource Selection to Indicate UE Capabilities

In some wireless networks in accordance with example embodiments of thedisclosure, one or more separate sets of resources for preambletransmission may be used to enable a UE to indicate a UE capability to abase station. For example, in an NR system, a gNB may configure separatesets (e.g., nonoverlapping sets) of RACH occasion (RO) resourcescorresponding to different CE capabilities of a UE. A UE may then selectand use one of the sets of resources for preamble transmission, forexample, during a 4-step RACH procedure, to indicate its CE capabilities(e.g., ability to send msg3 with repetitions) to the gNB.

FIG. 8 illustrates an example of a scheme for using resource sets toindicate a UE capability such as the ability to send a contentionresolution message with repetitions in accordance with exampleembodiments of the disclosure. The embodiment illustrated in FIG. 8 maybe described in the context of an NR system, but the principles may beapplied to any other wireless network with RA procedures.

Referring to FIG. 8, for each synchronization signal block (SSB), twosets of time/frequency resources may be configured for preambletransmission (e.g., during a 4-step RACH procedure). One set (e.g., set1 which may include resource sets RO1 ₁ through RO1 _(N)) may be used toindicate that the UE may not have CE capabilities to report to a gNB,while another set (e.g., set 2 which may include resource sets RO2 ₁through RO2 _(M)) may be used to indicate that the UE may have CEcapabilities (e.g., the ability to send msg3 with repetitions) to reportto the gNB. A UE without CE capabilities (non-CE UE) 802 may select aset of resources from set 1 and use the selected resources to send apreamble to the gNB to indicate a lack of one or more CE capabilities.Alternatively, a UE with CE capabilities 804 may select a set ofresources from set 2 and use the selected resources to send a preambleto the gNB to indicate the presence of one or more CE capabilities suchas the ability to send msg3 with repetitions.

Moreover, as shown in FIG. 8, a UE 804 having some CE capabilities maystill use the illustrated scheme to indicate to the gNB that it may nothave a specific capability (e.g., the ability to send msg3 withrepetitions) by selecting a set of resources from set 1.

In some embodiments, a combination of preamble grouping and resourceselection may be used to indicate a UE capability to a base station inaccordance with example embodiments of the disclosure. For example, insome embodiments, some RO resources may be duplicated across both setsof RO resources, and when one of the duplicated RO resources areselected, preamble grouping may be used to differentiate between UEcapabilities.

Resource Allocation for Contention Resolution Message Repetitions

In some wireless networks in accordance with example embodiments of thedisclosure, at least some resources for sending contention resolutionmessages with repetitions may be allocated independently, in a coupledmanner, or in any other suitable manner. Moreover, at least someresources for sending contention resolution messages with repetitionsmay be allocated dynamically, semi-statically, or in any other suitablemanner.

For purposes of illustration, a msg3 transmission in an NR system may bescheduled such that a UE may send an initial msg3 followed by K−1repetitions of msg3. (Thus, a total of K instances of the msg3 payloadmay be sent from the UE to the gNB). Each of these instances of msg3 maybe sent using a specified set of resources which may includetime/frequency resources, demodulation reference signal (DMRS)resources, and/or the like, as well as and a PUSCH transmissionconfiguration which may include an MCS value, an RV index, and/or thelike. (Thus, in some embodiments, a channel configuration such as aPUSCH transmission configuration may be considered part of a set ofresources.)

In some embodiments, the gNB may schedule a msg3 transmission withrepetitions where the set of resources (including PUSCH configurations)used for each of the instances of msg3 (e.g., the initial sending ofmsg3 and any repetitions of msg3) may be configured independently. Forexample, each instance of msg3 may have different time/frequencyresources, DMRS resources, MCS value, RV index, and/or the like. Theseresources (including configuration parameters) for one instance of msg3may or may not coincide with the corresponding values of anotherinstance. Such an allocation may provide the gNB with flexibility toimprove or optimize the UE sending of the instances of msg3. Forexample, the gNB may inform the UE to use an increasing amount ofresources for each repetition of msg3 in an attempt to increase thelikelihood of the UE to successfully delivering msg3. As anotherexample, the gNB may change the allocated resources of the UE for therepetitions of msg3 to better fit the scheduling considerations of thegNB.

FIG. 9 illustrates an example of a scheme for sending a contentionresolution message with repetitions using independent resourceallocation in accordance with example embodiments of the disclosure. Theembodiment illustrated in FIG. 9 may be described in the context of anNR system, but the principles may be applied to any other wirelessnetwork with RA procedures.

In the embodiment illustrated in FIG. 9, a first instance of msg3 (e.g.,an initial msg3) 902 may be sent with first time and frequency resourcesas indicated by the time and frequency axes, as well as resources MCS:1and RV:1. A second instance of msg3 (e.g., a first repetition of msg3)904 may be sent with second time and frequency resources as indicated bythe time and frequency axes, as well as resources MCS:3 and RV:2. Athird instance of msg3 (e.g., a second repetition of msg3) 906 may besent with third time and frequency resources as indicated by the timeand frequency axes, as well as resources MCS:3 and RV:3. Thus, resourcesfor sending all three instances of msg3 may be allocated independently.

In some other embodiments, a gNB may configure sets of resources (whichmay include PUSCH configurations) for repetitions of msg3 in a coupledmanner. For example, multiple instances of msg3 may be configured to besent with the same or similar sets of resources (which may include PUSCHtransmission configurations). For example, a gNB may allocate the samefrequency resources for all instances of msg3 while varying the timeresources for each instance or vice versa. As another example, the gNBmay allocate different frequency resources for repetitions within twogroups of repetitions, while allocating the same frequency resources forall repetitions within each group. Similar techniques may be used forconfiguring other resource parameters such as MCS value, RV index,and/or the like for repetitions.

FIG. 10 illustrates an example of a scheme for sending a contentionresolution message with repetitions using coupled resource allocation inaccordance with example embodiments of the disclosure. The embodimentillustrated in FIG. 10 may be described in the context of an NR system,but the principles may be applied to any other wireless network with RAprocedures.

In the embodiment illustrated in FIG. 10, a first instance of msg3(e.g., an initial msg3) 1002 may be sent with time and frequencyresources as indicated by the time and frequency axes, as well asresources MCS:1 and RV:1. A second instance of msg3 (e.g., a firstrepetition of msg3) 1004 may be sent with the same time and frequencyresources as the first instance 1002 as indicated by the time andfrequency axes, as well as the same MCS value (MCS:3) but a different RVvalue (RV:2). A third instance of msg3 (e.g., a second repetition ofmsg3) 1006 may be sent the same time and frequency resources as instance1002 as indicated by the time and frequency axes, as well as the sameMCS value (MCS:3) but a different RV value (RV:3). Thus, the initialmsg3 and both repetitions of msg3 may be sent with the same time andfrequency resources and MCS value, but different RV values.

In some embodiments, and depending on the implementation details, theindependent and/or coupled allocation techniques described herein mayreduce the overhead incurred when specifying the resource allocation formsg3 repetitions to the UE, and/or may provide a simple resourceallocation mechanism.

In some wireless networks in accordance with example embodiments of thedisclosure, a base station may indicate resources to be used by a UE forsending a contention resolution message with repetitions dynamically.For example, in an NR system, the allocated resources may be changedeach time the UE performs 4-step RACH and attempts a msg3 transmission.Because the resources for msg3 allocations may be indicated to the UEeach time the UE performs a 4-step RACH (e.g., dynamic scheduling whichmay also be referred to as allocation or configuration), informationabout the resource allocation may be sent to the UE dynamically.

In some wireless networks in accordance with example embodiments of thedisclosure, various techniques may be used to indicate schedulinginformation to a UE for sending a contention resolution message withrepetitions. For example, in some embodiments, a UE may be sentinformation about resource allocation in the UL grant scheduling msg3.In such an embodiment, the UL grant may include information such as thenumber of instances (K) of msg3, the time and frequency resources usedfor each instance, and/or other information about the PUSCHconfiguration associated with each instance of msg3. In some otherembodiments, a UE may be provided with the information to indicateresource allocation via the scheduling DCI of msg2. For example, the DCIformat used for scheduling msg2 transmissions may carry fields that mayinclude information to inform the UE of the resource allocations andPUSCH configurations of the initial sending of msg3 and one or morerepetitions.

In some other embodiments, a gNB may inform a UE semi-statically of theresources to use for sending an initial msg3 and repetitions of msg3.For example, the UE may be provided with information about the resourceallocation for msg3 transmissions via, e.g., RRC signaling. In such anembodiment, for any attempted 4-step RACH by the UE, while such resourceallocation is configured, the UE may attempt to send an initial msg3 andany repetitions of msg3 using a resource allocation that may bepre-configured. For example, the UE may be provided with informationabout a PUSCH configuration for a set of K msg3 instances such as theMCS value, RV index, and/or the like. Additionally, the UE may beprovided with time/frequency resources to be used for the set of K msg3instances. In such an embodiment, when the UE attempts to send aninitial msg3 and one or more repetitions of msg3 during a 4-step RACHprocedure, the UE may then pre-configured resources (which may includePUSCH configurations).

In some further embodiments, a gNB may indicate the resources for a UEto use for sending an initial msg3 and repetitions using a combinationof dynamically-indicated information and semi-statically-indicatedinformation. For example, the UE may be configured with some informationabout the resource allocation (which may include a PUSCH configuration)to be used for msg3 via, for example, RRC signaling. Additionally, thegNB may indicate to a UE some other information about the resourceallocations (which may include a PUSCH configuration) to be used formsg3 while the msg3 transmission is being scheduled via, for example, aUL grant and/or scheduling DCI. For example, a UE may be pre-configuredwith an MCS value and/or an RV index to be used for sending msg3, whilebeing informed dynamically with information related to thetime/frequency resource allocations to be used for sending msg3.

Conveying Resource Allocation

In some wireless networks in accordance with example embodiments of thedisclosure, various techniques may be used to represent resourceallocations and/or convey information about such resource allocations toa UE, a base station, and/or the like.

For example, in some embodiments of an NR system, a gNB may convey tothe UE a collection of resource allocations (which may include PUSCHconfiguration parameters), where each item in the collection maycorrespond to resources for one transmission of msg3 which may includethe initial msg3 and any repetitions. In some other embodiments, eachitem in the collection may correspond to resources for one instance ofmsg3, where an instance of msg3 may refer to an initial msg3 or anyrepetition of msg3 Thus, in these embodiments, one item may be forsending an initial msg3, a second item may be for sending a firstrepetition of msg3, and a third item may be for sending a secondrepetition of msg3.

In some embodiments, for purposes of illustration, a collection ofresource allocations may be referred to as a list, however, therepresentation is not necessarily limited to lists and may beimplemented with any suitable technique for representing information ona collection of resource allocations.

In some example embodiments, each item in a list may include one or morevariables to inform the UE of the resource allocations that may be usedto send a contention resolution message. For example, a gNB may decideto schedule a UE to send K instances of msg3 (e.g., a first msg3 and K−1repetitions of msg3). To implement this, the gNB may send to the UE alist that may include K items, where each item may include configurationinformation for sending a corresponding instance of msg3. Thus, a listmay directly contain the configuration information to be used by the UEfor sending msg3 instances. A list may be conveyed to the UE through aUL grant, a DCI, and/or any other mechanism. Depending on theimplementation details, this type of embodiment may provide flexibility,for example, in terms of configuring the transmissions of msg3. In someembodiments, the length of such a list (e.g., the number of items in thelist) may indicate the number of instances K of a contention resolutionmessage, and therefore a dedicated variable for K may be omitted.

In some other example embodiments, a gNB can provide the UE with one ormore indices to one or more configuration lists that may bepre-configured with resource allocations. For example, a list mayinclude a collection of items, where each item may include configurationinformation that may be used to send a potential instance of msg3. ThegNB may then provide to the UE one or more indices to one or moreentries of the one or more configuration lists, where the indices mayindicate which entries are to be used with the scheduled msg3 instances.Thus, the one or more lists may contain one or more sets of potentialconfiguration information, where a set or subset may later be selectedbased on one or more indices. The one or more indices may be provided tothe UE, for example, semi-statically (e.g., through RRC signaling and/orthe like), dynamically (e.g., through a UL grant, DCI, and/or the like)or through any other suitable mechanism. As mentioned above, the use oflists in this context is for purposes of illustration, and thepre-configured information may be represented in any suitable form.

In some embodiments, a UE may be configured with a list of possibleresources including time and/or frequency resources, and/or resourcesbased on any other parameters. A gNB may then convey to the UE an indexwhich may map to an entry in such a list that determines the resourcesto be used for sending a contention resolution message. Such a list mayalso be used to indicate a number of repetitions, for example, by one ormore adding entries corresponding to the number of repetitions. In someembodiments, a UE may also be configured with different lists, andvarious parameters may be used as indices to different lists and/ortables. The collective use of these lists and indices may allow the UEto determine the resources to use for sending some or more instances ofa contention resolution message.

FIG. 11 illustrates an example of a scheme for representing and/orconveying resource allocations using a list in accordance with exampleembodiments of the disclosure. FIG. 12 illustrates an example of ascheme for representing and/or conveying resource allocations usingmultiple lists in accordance with example embodiments of the disclosure.The embodiments illustrated in FIGS. 11 and 12 may be described in thecontext of an NR system, but the principles may be applied to any otherwireless network with RA procedures.

In the embodiment illustrated in FIG. 11, a configuration list mayinclude multiple entries (e.g., entry 1, entry 2, . . . entry N). Eachentry may include one or more resources to use for sending a contentionresolution message with repetitions. A base station such as a gNB mayprovide a UE with an index I that the UE may use to determine whichentry contains the resources to use.

In the embodiment illustrated in FIG. 12, multiple configuration lists(e.g., configuration list 1, configuration list 2, configuration list 3,etc., may each include multiple entries (e.g., entries 1 . . . N inconfiguration list 1, entries 1 . . . M in configuration list 2, entries1 . . . K in configuration list 3, etc.) A base station such as a gNBmay provide a UE with one or more indices 11, 12, 13, etc., that the UEmay use to determine which entry or entries contains the resources touse for sending a contention resolution message with repetitions.

In some embodiments, an example of a configuration list that may be usedto represent and/or convey information about resource allocation forsending a contention resolution message with repetitions may be a PUSCHtime allocation resource table. A PUSCH time allocation table mayinclude a collection of possible time allocations that a UE may use forPUSCH transmissions based on one or more indications from a gNB. Forexample, when a PUSCH is scheduled by a gNB, the gNB may provide the UEwith an index to the PUSCH time allocation table which indicates whichtime resource allocations to be used for this particular PUSCH.

Table 2 illustrates an example of a time allocation table that may beused for scheduling msg3 with repetitions in accordance with exampleembodiments of the disclosure. Each row in Table 2 may indicate a PUSCHmapping type, the parameter K₂, the start symbol S, the length of thePUSCH duration L, and/or the number of repetitions (which may includethe initial sending of msg3 and any repetitions). Table 3 illustratessome configurations for the parameter j shown in Table 2.

TABLE 2 PUSCH mapping Number of Row index type K₂ S L Repetitions 1 TypeA j 0 14 3 2 Type A j 0 12 3 3 Type A j 0 10 3 4 Type B j 2 10 3 5 TypeB j 4 10 2 6 Type B j 4 8 2 7 Type B j 4 6 2 8 Type A j + 1 0 14 2 9Type A j + 1 0 12 3 10 Type A j + 1 0 10 3 11 Type A j + 2 0 14 3 12Type A j + 2 0 12 3 13 Type A j + 2 0 10 2 14 Type B j 8 6 2 15 Type Aj + 3 0 14 2 16 Type A j + 3 0 10 2

TABLE 3 μ_(PUSCH) j 0 1 1 1 2 2 3 3

In some embodiments, Table 2 may be used a UE and gNB to schedule msg3with repetitions if the UE indicates (for example, through preamblegrouping and/or RO index as described above) that it is capable ofsending msg3 with repetition. An index to the PUSCH time allocationresource table may then point to an entry in that table that may givethe UE the necessary information to determine time allocations for msg3transmissions. In some embodiments, the gNB may configure the UE withtwo separate PUSCH time allocation tables, for example, one without the“number of repetitions” for scheduling PUSCH operations for UEs withoutCE capabilities such as msg3 repetitions, and one with an additional“number of repetitions” field for msg3 scheduling with repetitions. Insome alternative embodiments, a single table with a “number ofrepetitions” field may be used. In this case, the “number ofrepetitions” may be ignored by UEs without CE capabilities, and by UEswith the capability of sending msg3 with repetitions.

In some embodiments, one or more of the methods described above for theuse of a PUSCH time allocation table may provide the gNB with theability to schedule a UE to send msg3 with repetition. However, in somesituations, if a UE indicates msg3 repetition capability, it may stillbe beneficial for the gNB to schedule msg3 without repetitions if thegNB decides to do so. To accommodate this type of situation, the gNB mayindicate to the UE which “time allocation table” may be used for sendingmsg3 (in case two separate tables are configured) or whether to use the“number of repetitions” field (in case a single table with a “number ofrepetitions” field is used). This indication may be given dynamically tothe UE (e.g., in a UL grant or in a scheduling DCI) or it may beconfigured semi-statically. For example, this indication may beimplemented by using a one-bit field (e.g., in the UL grant or thescheduling DCI, or as an additional RRC parameter). In this example, ifthe bit has a first value, no repetition may be used, and if it has theopposite value, then repetition may be used.

In some further embodiments of a mechanism for time resource allocationsof msg3 with repetitions, one or more time resource allocations forrepetitions may be determined by determining a number K of instances ofmsg3 and time offset t between two consecutive transmissions. The timeoffset t can be expressed, for example, in terms of time units such assymbols, slots or subframes. In such an embodiment, the assumedSub-Carrier Spacing (SCS) when determining the time offset may be basedon the active Bandwidth Part (BWP) or another SCS which may beexplicitly and dynamically indicated to the UE (e.g., in the UL grant orscheduling DCI) or semi-statically configured (e.g., through RRC). Thetime offset t may also be provided, for example, through an additionalfield in the time allocation table, and/or as a separate parameterspecified dynamically or semi-statically.

In some further embodiments of a mechanism for time resource allocationsof msg3 with repetitions, one or more frequency resource allocations forrepetitions may be determined by determining a frequency offset fbetween two consecutive transmissions. The frequency offset f may beexpressed, for example, in terms of Physical Resource Blocks (PRBs) orpartial PRBs. In such an embodiment, the assumed SCS may also be basedon the active BWP or another SCS which is explicitly and dynamicallyindicated to the UE (e.g., in the UL grant or scheduling DCI) orsemi-statically configured (e.g., through RRC). The frequency offset fmay also be provided, for example, through an additional field in thefrequency allocation table, or as a separate parameter specifieddynamically or semi-statically.

Monitoring Responses with Repetitions

In some wireless networks in accordance with example embodiments of thedisclosure, a UE may monitor for a response from a base station, forexample, by continuously monitoring after sending an initial contentionresolution message, and stopping after a RAR window duration aftersending the last repetition of the contention resolution message. Insome embodiments in which a UE may not be able to perform simultaneousUL and DL transmissions, one or more monitoring durations may excludethe times used by the UE for retransmissions and/or adhering to atimeline (e.g., accounting for switching time, and/or the like). In someother embodiments, the UE may only begin monitoring for a response fromthe base station after sending the final repetition of the contentionresolution message.

In some embodiments of an NR system, a UE may start a monitoring windowhaving a duration determined by the parameterra-ContentionResolutionTimer, during which it may monitor for a DCIformat 1_0 scheduling the PDSCH carrying msg4.

In a first embodiment of a system that may allow msg3 to be sent withrepetitions, the UE may start the monitoring window after the end ofsending the initial msg3. Depending on the implementation details, thismay allow the UE to efficiently complete the RACH procedure after atleast one instance of msg3 is correctly received by the gNB. In such anembodiment, the duration of the window may be set sufficiently long toaccount for possible msg4 transmissions in response to both the initialmsg3 and the repetitions of msg3. This may be implemented, for example,by setting the parameter ra-ContentionResolution Timer to a large enoughvalue to accommodate the necessary duration. Alternatively, this may beimplemented by allowing the monitoring window to restart after sendingeach msg3 repetition. In some embodiments, the UE may be allowed toswitch between sending msg3 repetitions and monitoring PDCCH occasions.Depending on the implementation details, this may introduce a sufficienttimeline to account for a switching time constraint of the UE.

In a first embodiment of a system that may allow msg3 to be sent withrepetitions, the UE may start the monitoring window after the end of thelast msg3 repetition. Depending on the implementation details, this maysimplify the procedure, for example, in terms of UE implementation.

Power Adaptation for Contention Resolution Messages

In some wireless networks in accordance with example embodiments of thedisclosure, a UE may perform power adaptation while sending contentionresolution messages. In some embodiments, multiple sets of poweradaptation parameters may be configured. For example, a first set ofpower adaptation parameters may be used for UEs that may have certain CEcapabilities such as sending contention resolution messages withrepetitions, while a second set of power adaptation parameters may beused for UEs that may not have one or more CE capabilities.

In some embodiments, each set of power adaptation parameters may includea collection of parameters that may be used for power adaptation. In anNR system, examples of such parameters may include powerRampingStep,msg3-Delta, msg3-Alpha and/or powerRampingStep. Any or all of theparameters may be the same or different among sets. In some embodiments,the gNB may indicate to the UE which set of parameters to use, forexample, in a DCI scheduling msg3 and its repetitions. Such anindication may be implemented, for example, in the scheduling DCI or inthe UL grant. In some embodiments, the UE may also revert to apre-configured set of parameters if no indication is provided in the ULgrant or in the scheduling DCI.

In some embodiments, a UE may have a UE capability that may indicate howmany different power adaptation parameter sets it can support for msg3.In such an embodiment, the UE may then indicate this capability to thegNB, for example, via preamble grouping, RO extensions, and/or the like.

In some embodiments, when scheduling msg3, a gNB may inform the UE ofwhich power adaptation parameter set to use when sending an initial msg3and/or repetitions of msg3. In some embodiments, a gNB may be limited toindicating to the UE only parameter sets the UE may actually use (forexample, according to a UE capability that the UE has indicated to thegNB). In some other embodiments, the gNB may indicate a parameter set touse regardless of the UE's capability so use the parameter set; in thiscase, in some implementations, the UE may choose another set ofparameters to use which matches its UE capability.

User Equipment

FIG. 13 illustrates an example embodiment of a UE in accordance withexample embodiments of the disclosure. The embodiment 1300 illustratedin FIG. 13 may include a radio transceiver 1302 and a controller 1304which may control the operation of the transceiver 1302 and/or any othercomponents in the UE 1300. The UE 1300 may be used, for example, toimplement any of the UE functionality described in this disclosure suchas UE random access functionality, sending contention resolutionmessages with repetitions, and/or the like.

The transceiver 1302 may transmit/receive one or more signals to/from abase station, and may include an interface unit for suchtransmissions/receptions. For example, the transceiver 1302 may receiveMIB/SIB information, random access related configuration information,and/or one or more synchronization signals from a base station. It maytransmit one or more random access preambles, PRACH, PUSCH, or PUCCHtransmissions to a base station. It may receive responses thereto fromthe base station, for example, msg2 and/or msg4 transmissions, RARs,and/or the like using PDSCH, PDCCH, and/or the like.

The controller 1304 may include, for example, one or more processors1306 and a memory 1308 which may store instructions for the one or moreprocessors 1306 to execute code to implement any of the UE functionalitydescribed in this disclosure. For example, the controller 1304 may beused to implement a method for sending contention resolution messageswith repetitions. In some embodiments, the controller 1304 may be usedto implement, may be implemented as, may include, and/or may be includedas part of, a medium access control (MAC) layer.

Base Station

FIG. 14 illustrates an example embodiment of a base station inaccordance with example embodiments of the disclosure. The embodiment1400 illustrated in FIG. 14 may include a radio transceiver 1402 and acontroller 1404 which may control the operation of the transceiver 1402and/or any other components in the base station 1400. The base station1400 may be used, for example, to implement any of the base stationfunctionality described in this disclosure such as base station randomaccess functionality, receiving contention resolution messages withrepetitions, and/or the like.

The transceiver 1402 may transmit/receive one or more signals to/from abase station, and may include an interface unit for suchtransmissions/receptions. For example, the transceiver 1402 may transmitMIB/SIB information, random access related configuration information,and/or one or more synchronization signals to a UE. It may receive oneor more random access preambles, PRACH, PUSCH, or PUCCH transmissions,and/or the like from a UE. It may transmit responses thereto to the UE,for example, msg2 and/or msg4 transmissions, RAR, and/or the like usingPDSCH, PDCCH, and/or the like.

The controller 1404 may include, for example, one or more processors1406 and a memory 1408 which may store instructions for the one or moreprocessors 1406 to execute code to implement any of the base stationfunctionality described in this disclosure. For example, the controller1404 may be used to implement one or more techniques for receivingcontention resolution messages with repetitions from a UE. In someembodiments, the controller 1404 may be used to implement, may beimplemented as, may include, and/or may be included as part of, a mediumaccess control (MAC) layer.

In the embodiment illustrated in FIGS. 13 and 14, the transceivers 1302and 1402 may be implemented with various components to receive and/ortransmit RF signals such as amplifiers, filters, modulators and/ordemodulators, A/D and/or DA converters, antennas, switches, phaseshifters, detectors, couplers, conductors, transmission lines, and/orthe like. The controllers 1304 and 1404 may be implemented withhardware, software, and/or any combination thereof. For example, full orpartial hardware implementations may include combinational logic,sequential logic, timers, counters, registers, gate arrays, amplifiers,synthesizers, multiplexers, modulators, demodulators, filters, vectorprocessors, complex programmable logic devices (CPLDs), fieldprogrammable gate arrays (FPGAs), state machines, data converters suchas ADCs and DACs, and/or the like. Full or partial softwareimplementations may include one or more processor cores, memories,program and/or data storage, and/or the like, which may be locatedlocally and/or remotely, and which may be programmed to executeinstructions to perform one or more functions of the controllers.

ADDITIONAL EMBODIMENTS

FIG. 15 illustrates an embodiment of a method for random access in awireless communication network in accordance with example embodiments ofthe disclosure. The method may begin at operation 1502. At operation1504, the method may send a contention resolution message for a randomaccess procedure from a user equipment (UE) to a base station through aphysical uplink channel in a wireless communication network. Atoperation 1506, the method may send a repetition of the contentionresolution message from the UE to the base station through the physicaluplink channel. The method may end at operation 1508.

In the embodiment illustrated in FIG. 15, the illustrated componentsand/or operations are exemplary only. Some embodiments may involvevarious additional components and/or operations not illustrated, andsome embodiments may omit some components and/or operations. Moreover,in some embodiments, the arrangement of components and/or temporal orderof the operations may be varied. Although some components may beillustrated as individual components, in some embodiments, somecomponents shown separately may be integrated into single components,and/or some components shown as single components may be implementedwith multiple components.

Although some embodiments have been described in the context of 5Gand/or new radio (NR) wireless networks, the principles may be appliedto any other types of systems having random access procedures. Thus, insome embodiments, PUSCH may refer to any physical uplink shared channel,PRACH may refer to any physical random access channel, gNB may refer toany type of base station, etc.

The embodiments disclosed herein may be described in the context ofvarious implementation details, but the principles of this disclosureare not limited to these or any other specific details. Somefunctionality has been described as being implemented by certaincomponents, but in other embodiments, the functionality may bedistributed between different systems and components in differentlocations. A reference to a component or element may refer to only aportion of the component or element. The use of terms such as “first”and “second” in this disclosure and the claims may only be for purposesof distinguishing the things they modify and may not indicate anyspatial or temporal order unless apparent otherwise from context. Areference to a first thing may not imply the existence of a secondthing. Moreover, the various details and embodiments described above maybe combined to produce additional embodiments according to the inventiveprinciples of this patent disclosure. Various organizational aids suchas section headings and the like may be provided as a convenience, butthe subject matter arranged according to these aids and the principlesof this disclosure are not defined or limited by these organizationalaids.

Since the inventive principles of this patent disclosure may be modifiedin arrangement and detail without departing from the inventive concepts,such changes and modifications are considered to fall within the scopeof the following claims.

1. A method comprising: sending a contention resolution message for arandom access procedure from a user equipment (UE) through a physicaluplink channel in a wireless communication network; and sending arepetition of the contention resolution message from the UE through thephysical uplink channel.
 2. The method of claim 1, wherein the physicaluplink channel comprises a physical uplink shared channel (PUSCH). 3.The method of claim 1, further comprising: selecting a preamble from afirst preamble group corresponding to a capability of the UE to send therepetition of the contention resolution message; and sending thepreamble from the UE.
 4. The method of claim 3, wherein selecting thepreamble from the first preamble group comprises selecting a preamblefrom a first preamble sub-group corresponding to the capability of theUE to send the repetition of the contention resolution message.
 5. Themethod of claim 1, further comprising: selecting a first set ofresources for a preamble transmission corresponding to a capability ofthe UE to send the repetition of the contention resolution message; andsending a preamble from the UE using the first set of resources.
 6. Themethod of claim 1, wherein the contention resolution message is sentusing a first set of resources.
 7. The method of claim 6, wherein therepetition of the contention resolution message is sent using a secondset of resources.
 8. The method of claim 7, wherein the first set ofresources is configured substantially independently of the second set ofresources.
 9. The method of claim 7, wherein a portion of the first setof resources is configured substantially the same as a portion of thesecond set of resources.
 10. The method of claim 7, wherein: the firstset of resources comprises a first repetition value (RV); and the secondset of resources comprises a second RV that is different from the firstRV.
 11. The method of claim 7, wherein: the first set of resourcescomprises a first RV; and the second set of resources comprises a secondRV that is the same as the first RV.
 12. The method of claim 6, wherein:the first set of resources has a first configuration for a firsttransmission comprising the contention resolution message; and the firstset of resources has a second configuration for a second transmissioncomprising the contention resolution message, wherein the secondconfiguration is substantially different from the first configuration.13. The method of claim 6, wherein: the first set of resources has afirst configuration for a first transmission comprising the contentionresolution message; and the first set of resources has a secondconfiguration for a second transmission comprising the contentionresolution message, wherein the second configuration is substantiallythe same as the first configuration.
 14. The method of claim 6, whereinthe first set of resources comprises an RV index.
 15. The method ofclaim 14, further comprising configuring the RV index dynamically. 16.The method of claim 14, further comprising configuring the RV indexsemi-statically.
 17. The method of claim 6, wherein the first set ofresources comprises a demodulation reference signal (DMRS)configuration.
 18. The method of claim 6, further comprising sending tothe UE an index to one or more resources of the first set of resources.19. The method of claim 1, further comprising monitoring a responsebased on completion of sending the contention resolution message. 20.The method of claim 1, further comprising monitoring a response based oncompletion of sending the repetition of the contention resolutionmessage.
 21. The method of claim 1, further comprising performing apower adaptation for the physical uplink channel.
 22. The method ofclaim 21, further comprising: configuring a first set of parameters forthe power adaptation; and configuring a second set of parameters for thepower adaptation.
 23. The method of claim 22, wherein the UE comprises afirst UE, the contention resolution message comprises a first contentionresolution message, the method further comprising: using the first setof parameters to send the first contention resolution message from thefirst UE using the physical uplink channel; and using the second set ofparameters to send a second contention resolution message from a secondUE through the physical uplink channel.
 24. The method of claim 22,further comprising changing one or more of the parameters between thecontention resolution message and the repetition of the contentionresolution message.
 25. An apparatus comprising: a user equipment (UE)for a wireless communication network, the UE comprising a controllerconfigured to: send a contention resolution message for a random accessprocedure through a physical uplink channel in the wirelesscommunication network; and send a repetition of the contentionresolution message through the physical uplink channel.
 26. Theapparatus of claim 25, wherein the physical uplink channel comprises aphysical uplink shared channel (PUSCH).
 27. An apparatus comprising: abase station for a wireless communication network, the base stationcomprising a controller configured to: receive a contention resolutionmessage for a random access procedure through a physical uplink channelin the wireless communication network; and receive a repetition of thecontention resolution message through the physical uplink channel. 28.The apparatus of claim 27, wherein the physical uplink channel comprisesa physical uplink shared channel (PUSCH).
 29. A method comprising:sending a contention resolution message for a random access procedurefrom a user equipment (UE) through a physical uplink channel in awireless communication network; and performing a power adaptation forthe physical uplink channel based on sending the contention resolutionmessage.
 30. The method of claim 29, further comprising: configuring afirst set of parameters for the power adaptation; and configuring asecond set of parameters for the power adaptation.